Cellulose ester/elastomer compositions

ABSTRACT

A cellulose ester composition is provided comprising at least one cellulose ester and at least one additive selected from the group consisting of a compatibilizer, and a plasticizer. Processes for producing the cellulose ester composition are also provided. In another embodiment, a cellulose ester/elastomer composition is provided comprising at least one elastomer, at least one cellulose ester; and at least one additive; wherein the additive is at least one selected from the group consisting of a compatibilizer and a plasticizer. Processes for producing the cellulose ester/elastomer composition is also provided as well as articles comprising the cellulose ester/elastomer composition.

RELATED APPLICATIONS

This application is a continuation in part application to U.S. patentapplication Ser. No. 13/170,606 filed on Jun. 28, 2011 which claimspriority to U.S. Provisional Application No. 61/359,582 filed Jun. 29,2010 now expired; and claims priority to U.S. Provisional ApplicationNos. 61/567,948, 61/567,950, 61/567,951, and 61/567,953 filed on Dec. 7,2011, the disclosures of which are incorporated herein by reference tothe extent they do not contradict the statements herein.

FIELD OF THE INVENTION

This invention belongs to the field of cellulose ester chemistry,particularly to cellulose esters comprising compatibilizers andoptionally, plasticizers. The invention also belongs to the field ofcellulose ester/elastomer compositions comprising at least one elastomerand at least one additive wherein the additive is at least one selectedfrom the group consisting of a compatibilizer and a plasticizer.Processes for producing the cellulose ester compositions and thecellulose ester/elastomer compositions are also provided.

BACKGROUND OF THE INVENTION

This invention relates to the dispersion of cellulose esters inelastomers as small particles to improve the mechanical and physicalproperties of the elastomer. Polar cellulose esters (CE) areincompatible with non-polar elastomers. In addition, high meltingcellulose esters do not melt at typical melt processing temperature ofelastomers. These factors make dispersion of cellulose esters intoelastomers difficult via most industrially utilized melt mixing process.Due to the above problems, cellulose esters are not an obvious choice asan additive to non-polar elastomers.

This invention can overcome these difficulties by using plasticizerswhere necessary to help reduce the melt temperature of cellulose estersand by using compatibilizers to help improve mixing and compatibility ofcellulose esters and elastomers. Although not wishing to be bound bytheory, it is believed that the compatibilizers used can also improvemechanical and physical properties of the cellulose ester/elastomercompositions by improving the interfacial interaction/bonding betweenthe cellulose ester and the elastomer. These cellulose ester/elastomercompositions can be used in rubber/elastomeric applications ranging fromtires, hoses, belts, gaskets, automotive parts, and the like.

A process of dispersing cellulose esters in elastomers involves meltingor softening cellulose esters so that the cellulose esters can flow andsubsequently break down into small particles (dispersion) under shearprocessing. After dispersion, the cellulose esters can re-solidify uponcooling to room temperature to reinforce the rubber. Therefore, theincorporation of cellulose ester into elastomeric compositions can lowerMooney viscosity which can help with the processing of the compositionthrough equipment, such as, mixers, calenders, extruders, and moldingequipment. It can also provide longer scorch safety which provides for alonger safety time during processing. Shorter cure times can also beobtained which allows for faster turnaround time in curing molds andpresses. The addition of the cellulose ester to the elastomer can alsoprovide for higher break stress/strain, higher low strain modulus, andhigher tear strength providing a tougher and stiffer composition.Finally, the addition of the cellulose ester can provide a lower tandelta at 30 C which allows for lower heat buildup and lower hysteresis.

BRIEF SUMMARY OF THE INVENTION

In one embodiment of the invention, a cellulose ester composition isprovided comprising at least one cellulose ester, at least onecompatibilizer, and optionally, and at least one plasticizer.

In another embodiment of the invention, a cellulose ester/elastomercomposition is provided comprising at least one elastomer, at least onecellulose ester, and at least one additive; wherein the additive is atleast one selected from the group consisting of a compatibilizer and aplasticizer.

In another embodiment of the invention, a process for producing thecellulose ester composition is provided comprising contacting at leastone cellulose ester, at least one compatibilizer, and optionally, atleast one plasticizer.

In another embodiment of the invention, a process for producing acellulose ester/elastomer composition is provided comprising mixing atleast one elastomer, at least one cellulose ester, and at least oneadditive for a sufficient time and temperature to disperse the celluloseester to produce the cellulose ester/elastomer composition; wherein theadditive is at least one selected from the group consisting of acompatibilizer and a plasticizer.

In another embodiment, an article is provided comprising the celluloseester/elastomer composition.

In another embodiment of the invention, a tire component is providedcomprising at least one elastomer, at least one filler, at least onecellulose ester, and at least one additive selected from the groupconsisting of at least one compatibilizer and at least one plasticizer.

Other inventions concerning the use of cellulose esters in elastomershave been filed in provisional applications by Eastman Chemical Companyon Dec. 7, 2011 entitled “Cellulose Esters in Pneumatic Tires”,“Cellulose Esters in Highly Filled Elastomeric Systems”, and “Processfor Dispersing Cellulose Esters into Elastomeric Compositions”; thedisclosures of which are hereby incorporated by reference to the extentthat they do not contradict the statements herein.

DETAILED DESCRIPTION

In one embodiment of the invention, a cellulose ester composition isprovided comprising at least one cellulose ester, at least onecompatibilizer, and optionally, at least one plasticizer.

The cellulose ester/elastomer composition of the present invention cancomprise at least about 1, 2, 3, 4, 5, or 10 parts per hundred rubber(“phr”) of at least one cellulose ester, based on the total weight ofthe elastomers. Additionally or alternatively, the celluloseester/elastomer composition of the present invention can comprise notmore than about 75, 50, 40, 30, or 20 phr of at least one celluloseester, based on the total weight of the elastomers. The term “phr,” asused herein, refers to parts of a respective material per 100 parts byweight of rubber or elastomer.

The cellulose ester utilized in this invention can be any that is knownin the art. The cellulose esters useful in the present invention can beprepared using techniques known in the art or can be commerciallyobtained, e.g., from Eastman Chemical Company, Kingsport, Tenn., U.S.A.

The cellulose esters of the present invention generally compriserepeating units of the structure:

wherein R¹, R², and R³ may be selected independently from the groupconsisting of hydrogen or a straight chain alkanoyl having from 2 to 10carbon atoms. For cellulose esters, the substitution level is usuallyexpressed in terms of degree of substitution (“DS”), which is theaverage number of substitutents per anhydroglucose unit (“AGU”).Generally, conventional cellulose contains three hydroxyl groups per AGUthat can be substituted; therefore, the DS can have a value between zeroand three. Alternatively, lower molecular weight cellulose mixed esterscan have a total degree of substitution ranging from about 3.08 to about3.5. Generally, cellulose is a large polysaccharide with a degree ofpolymerization from 700 to 2,000 and a maximum DS of 3.0. However, asthe degree of polymerization is lowered, as in low molecular weightcellulose mixed esters, the end groups of the polysaccharide backbonebecome relatively more significant, thereby resulting in a DS rangingfrom about 3.08 to about 3.5.

Because DS is a statistical mean value, a value of 1 does not assurethat every AGU has a single substituent. In some cases, there can beunsubstituted AGUs, some with two substitutents, and some with threesubstitutents. The “total DS” is defined as the average number ofsubstitutents per AGU. In one embodiment of the invention, the celluloseesters can have a total DS per AGU (DS/AGU) of at least about 0.5, 0.8,1.2, 1.5, or 1.7. Additionally or alternatively, the cellulose esterscan have a total DS/AGU of not more than about 3.0, 2.9, 2.8, or 2.7.The DS/AGU can also refer to a particular substituent, such as, forexample, hydroxyl, acetyl, butyryl, or propionyl. For instance, acellulose acetate can have a total DS/AGU for acetyl of about 2.0 toabout 2.5, while a cellulose acetate propionate (“CAP”) and celluloseacetate butyrate (“CAB”) can have a total DS/AGU of about 1.7 to about2.8.

The cellulose ester can be a cellulose triester or a secondary celluloseester. Examples of cellulose triesters include, but are not limited to,cellulose triacetate, cellulose tripropionate, or cellulose tributyrate.Examples of secondary cellulose esters include cellulose acetate,cellulose acetate propionate, and cellulose acetate butyrate. Thesecellulose esters are described in U.S. Pat. Nos. 1,698,049; 1,683,347;1,880,808; 1,880,560; 1,984,147, 2,129,052; and 3,617,201, which areincorporated herein by reference in their entirety to the extent they donot contradict the statements herein.

In one embodiment of the invention, the cellulose ester is selected fromthe group consisting of cellulose acetate, cellulose acetate propionate,cellulose acetate butyrate, cellulose triacetate, cellulosetripropionate, cellulose tributyrate, and mixtures thereof.

The degree of polymerization (“DP”) as used herein refers to the numberof AGUs per molecule of cellulose ester. In one embodiment of theinvention, the cellulose esters can have a DP of at least about 2, 10,50, or 100. Additionally or alternatively, the cellulose esters can havea DP of not more than about 10,000, 8,000, 6,000, or 5,000.

In certain embodiments, the cellulose esters can have an inherentviscosity (“IV”) of at least about 0.2, 0.4, 0.6, 0.8, or 1.0deciliters/gram as measured at a temperature of 25° C. for a 0.25 gramsample in 100 ml of a 60/40 by weight solution ofphenol/tetrachloroethane. Additionally or alternatively, the celluloseesters can have an IV of not more than about 3.0, 2.5, 2.0, or 1.5deciliters/gram as measured at a temperature of 25° C. for a 0.25 gramsample in 100 ml of a 60/40 by weight solution ofphenol/tetrachloroethane.

In certain embodiments, the cellulose esters can have a falling ballviscosity of at least about 0.005, 0.01, 0.05, 0.1, 0.5, 1, or 5pascals-second (“Pa·s”). Additionally or alternatively, the celluloseesters can have a falling ball viscosity of not more than about 50, 45,40, 35, 30, 25, 20, or 10 Pa·s.

In certain embodiments, the cellulose esters can have a hydroxyl contentof at least about 1.2, 1.4, 1.6, 1.8, or 2.0 weight percent.

In certain embodiments, the cellulose esters useful in the presentinvention can have a weight average molecular weight (M_(w)) of at leastabout 5,000, 10,000, 15,000, or 20,000 as measured by gel permeationchromatography (“GPC”). Additionally or alternatively, the celluloseesters useful in the present invention can have a weight averagemolecular weight (M_(w)) of not more than about 400,000, 300,000,250,000, 100,000, or 80,000 as measured by GPC. In another embodiment,the cellulose esters useful in the present invention can have a numberaverage molecular weight (M_(w)) of at least about 2,000, 4,000, 6,000,or 8,000 as measured by GPC. Additionally or alternatively, thecellulose esters useful in the present invention can have a numberaverage molecular weight (M_(n)) of not more than about 100,000, 80,000,60,000, or 40,000 as measured by GPC.

In certain embodiments, the cellulose esters can have a glass transitiontemperature (“Tg”) of at least about 50° C., 55° C., 60° C., 65° C., 70°C., 75° C., or 80° C. Additionally or alternatively, the celluloseesters can have a Tg of not more than about 200° C., 190° C., 180° C.,170° C., 160° C., 150° C., 140° C., or 130° C.

In one embodiment of the present invention, the cellulose estersutilized in the cellulose ester/elastomer compositions have notpreviously been subjected to fibrillation or any other fiber-producingprocess. In such an embodiment, the cellulose esters are not in the formof fibrils and can be referred to as “non-fibril.”

The cellulose esters can be produced by any method known in the art.Examples of processes for producing cellulose esters are taught inKirk-Othmer, Encyclopedia of Chemical Technology, 5th Edition, Vol. 5,Wiley-Interscience, New York (2004), pp. 394-444. Cellulose, thestarting material for producing cellulose esters, can be obtained indifferent grades and from sources such as, for example, cotton linters,softwood pulp, hardwood pulp, corn fiber and other agricultural sources,and bacterial celluloses.

One method of producing cellulose esters is by esterification. In such amethod, the cellulose is mixed with the appropriate organic acids, acidanhydrides, and catalysts and then converted to a cellulose triester.Ester hydrolysis is then performed by adding a water-acid mixture to thecellulose triester, which can be filtered to remove any gel particles orfibers. Water is added to the mixture to precipitate out the celluloseester. The cellulose ester can be washed with water to remove reactionby-products followed by dewatering and drying.

The cellulose triesters that are hydrolyzed can have three substitutentsselected independently from alkanoyls having from 2 to 10 carbon atoms.Examples of cellulose triesters include cellulose triacetate, cellulosetripropionate, and cellulose tributyrate or mixed triesters of cellulosesuch as cellulose acetate propionate and cellulose acetate butyrate.These cellulose triesters can be prepared by a number of methods knownto those skilled in the art. For example, cellulose triesters can beprepared by heterogeneous acylation of cellulose in a mixture ofcarboxylic acid and anhydride in the presence of a catalyst such asH₂SO₄. Cellulose triesters can also be prepared by the homogeneousacylation of cellulose dissolved in an appropriate solvent such asLiCl/DMAc or LiCl/NMP.

Those skilled in the art will understand that the commercial term ofcellulose triesters also encompasses cellulose esters that are notcompletely substituted with acyl groups. For example, cellulosetriacetate commercially available from Eastman Chemical Company, Inc.,Kingsport, Tenn., U.S.A., typically has a DS from about 2.85 to about2.95.

After esterification of the cellulose to the triester, part of the acylsubstitutents can be removed by hydrolysis or by alcoholysis to give asecondary cellulose ester. Secondary cellulose esters can also beprepared directly with no hydrolysis by using a limiting amount ofacylating reagent. This process is particularly useful when the reactionis conducted in a solvent that will dissolve cellulose.

In another embodiment of the invention, low molecular weight mixedcellulose esters can be utilized, such as those disclosed in U.S. Pat.No. 7,585,905, which is incorporated herein by reference to the extentit does not contradict the statements herein.

In one embodiment of the invention, a low molecular weight mixedcellulose ester is utilized that has the following properties: (A) atotal DS/AGU of from about 3.08 to about 3.50 with the followingsubstitutions: a DS/AGU of hydroxyl of not more than about 0.70, aDS/AGU of C3/C4 esters from about 0.80 to about 1.40, and a DS/AGU ofacetyl of from about 1.20 to about 2.34; an IV of from about 0.05 toabout 0.15 dL/g, as measured in a 60/40 (wt./wt.) solution ofphenol/tetrachloroethane at 25° C.; a number average molecular weight offrom about 1,000 to about 5,600; a weight average molecular weight offrom about 1,500 to about 10,000; and a polydispersity of from about 1.2to about 3.5.

In another embodiment of the invention, a low molecular weight mixedcellulose ester is utilized that has the following properties: a totalDS/AGU of from about 3.08 to about 3.50 with the followingsubstitutions: a DS/AGU of hydroxyl of not more than about 0.70; aDS/AGU of C3/C4 esters from about 1.40 to about 2.45, and DS/AGU ofacetyl of from about 0.20 to about 0.80; an IV of from about 0.05 toabout 0.15 dL/g, as measured in a 60/40 (wt./wt.) solution ofphenol/tetrachloroethane at 25° C.; a number average molecular weight offrom about 1,000 to about 5,600; a weight average molecular weight offrom about 1,500 to about 10,000; and a polydispersity of from about 1.2to about 3.5.

In yet another embodiment of the invention, a low molecular weight mixedcellulose ester is utilized that has the following properties: a totalDS/AGU of from about 3.08 to about 3.50 with the followingsubstitutions: a DS/AGU of hydroxyl of not more than about 0.70; aDS/AGU of C3/C4 esters from about 2.11 to about 2.91, and a DS/AGU ofacetyl of from about 0.10 to about 0.50; an IV of from about 0.05 toabout 0.15 dL/g, as measured in a 60/40 (wt./wt.) solution ofphenol/tetrachloroethane at 25° C.; a number average molecular weight offrom about 1,000 to about 5,600; a weight average molecular weight offrom about 1,500 to about 10,000; and a polydispersity of from about 1.2to about 3.5.

In certain embodiments, the cellulose esters utilized in this inventioncan also contain chemical functionality. In such embodiments, thecellulose esters are described herein as “derivatized,” “modified,” or“functionalized” cellulose esters.

Functionalized cellulose esters are produced by reacting the freehydroxyl groups of cellulose esters with a bifunctional reactant thathas one linking group for grafting to the cellulose ester and onefunctional group to provide a new chemical group to the cellulose ester.Examples of such bifunctional reactants include succinic anhydride,which links through an ester bond and provides acid functionality;mercaptosilanes, which links through alkoxysilane bonds and providesmercapto functionality; and isocyanotoethyl methacrylate, which linksthrough a urethane bond and gives methacrylate functionality.

In one embodiment of the invention, the functionalized cellulose esterscomprise at least one functional group selected from the groupconsisting of unsaturation (double bonds), carboxylic acids,acetoacetate, acetoacetate imide, mercapto, melamine, and long alkylchains.

Bifunctional reactants to produce cellulose esters containingunsaturation (double bonds) functionality are described in U.S. Pat.Nos. 4,839,230, 5,741,901, 5,871,573, 5,981,738, 4,147,603, 4,758,645,and 4,861,629; all of which are incorporated by reference to the extentthey do not contradict the statements herein. In one embodiment, thecellulose esters containing unsaturation are produced by reacting acellulose ester containing residual hydroxyl groups with anacrylic-based compound and m-isopropyenyl-α,α′-dimethylbenzylisocyanate. The grafted cellulose ester is a urethane-containing producthaving pendant (meth)acrylate and α-methylstyrene moieties. In anotherembodiment, the cellulose esters containing unsaturation are produced byreacting maleic anhydride and a cellulose ester in the presence of analkaline earth metal or ammonium salt of a lower alkyl monocarboxylicacid catalyst, and at least one saturated monocarboxylic acid have 2 to4 carbon atoms. In another embodiment, the cellulose esters containingunsaturation are produced from the reaction product of (a) at least onecellulosic polymer having isocyanate reactive hydroxyl functionality and(b) at least one hydroxyl reactive poly(α,β ethyleneically unsaturated)isocyanate.

Bifunctional reactants to produce cellulose esters containing carboxylicacid functionality are described in U.S. Pat. Nos. 5,384,163, 5,723,151,and 4,758,645; all of which are incorporated by reference to the extentthey do not contradict the statements herein. In one embodiment, thecellulose esters containing carboxylic acid functionality are producedby reacting a cellulose ester and a mono- or di-ester of maleic orfurmaric acid, thereby obtaining a cellulose derivative having doublebond functionality. In another embodiment, the cellulose esterscontaining carboxylic acid functionality has a first and second residue,wherein the first residue is a residue of a cyclic dicarboxylic acidanhydride and the second residue is a residue of an oleophilicmonocarboxylic acid and/or a residue of a hydrophilic monocarboxylicacid. In yet another embodiment, the cellulose esters containingcarboxylic acid functionality are cellulose acetate phthalates, whichcan be prepared by reacting cellulose acetate with phthalic anhydride.

Bifunctional reactants to produce cellulose esters containingacetoacetate functionality are described in U.S. Pat. No. 5,292,877,which is incorporated by reference to the extent it does not contradictthe statements herein. In one embodiment, the cellulose esterscontaining acetoacetate functionality are produced by contacting: (i)cellulose; (ii) diketene, an alkyl acetoacetate, 2,2,6, trimethyl-4H1,3-dioxin-4-one, or a mixture thereof, and (iii) a solubilizing amountof solvent system comprising lithium chloride plus a carboxamideselected from the group consisting of 1-methyl-2-pyrrolidinone, N,Ndimethylacetamide, or a mixture thereof.

Bifunctional reactants to produce cellulose esters containingacetoacetate imide functionality are described in U.S. Pat. No.6,369,214, which is incorporated by reference to the extent it does notcontradict the statements herein. Cellulose esters containingacetoacetate imide functionality are the reaction product of a celluloseester and at least one acetoacetyl group and an amine functionalcompound comprising at least one primary amine.

Bifunctional reactants to produce cellulose esters containing mercaptofunctionality are described in U.S. Pat. No. 5,082,914, which isincorporated by reference to the extent it does not contradict thestatements herein. In one embodiment of the invention, the celluloseester is grafted with a silicon-containing thiol component which iseither commercially available or can be prepared by procedures known inthe art. Examples of silicon-containing thiol compounds include, but arenot limited to, (3-mercaptopropyl)trimethoxysilane,(3-mercaptopropyl)-dimethyl-methoxysilane,(3-mercaptopropyl)dimethoxymethylsilane,(3-mercaptopropyl)dimethylchlorosilane,(3-mercaptopropyl)dimethylethoxysilane,(3-mercaptopropyl)diethyoxy-methylsilane, and(3-mercapto-propyl)triethoxysilane.

Bifunctional reactants to produce cellulose esters containing melaminefunctionality are described in U.S. Pat. No. 5,182,379, which isincorporated by reference to the extent it does not contradict thestatements herein. In one embodiment, the cellulose esters containingmelamine functionality are prepared by reacting a cellulose ester with amelamine compound to form a grafted cellulose ester having melaminemoieties grafted to the backbone of the anhydrogluclose rings of thecellulose ester. In one embodiment, the melamine compound is selectedfrom the group consisting of methylol ethers of melamine and aminoplastcarrier elastomers.

Bifunctional reactants to produce cellulose esters containing long alkylchain functionality are described in U.S. Pat. No. 5,750,677, which isincorporated by reference to the extent it does not contradict thestatements herein. In one embodiment, the cellulose esters containinglong alkyl chain functionality are produced by reacting cellulose incarboxamide diluents or urea-based diluents with an acylating reagentusing a titanium-containing species. Cellulose esters containing longalkyl chain functionality can be selected from the group consisting ofcellulose acetate hexanoate, cellulose acetate nonanoate, celluloseacetate laurate, cellulose palmitate, cellulose acetate stearate,cellulose nonanoate, cellulose hexanoate, cellulose hexanoatepropionate, and cellulose nonanoate propionate.

The plasticizer utilized in this invention can be any that is known inthe art that can reduce the melt temperature and/or the melt viscosityof the cellulose ester. The plasticizer can be either monomeric orpolymeric in structure. In one embodiment, the plasticizer is at leastone selected from the group consisting of a phosphate plasticizer,benzoate plasticizer, adipate plasticizer, a phthalate plasticizer, aglycolic acid ester, a citric acid ester plasticizer and ahydroxyl-functional plasticizer.

In one embodiment of the invention, the plasticizer can be selected fromat least one of the following: triphenyl phosphate, tricresyl phosphate,cresyldiphenyl phosphate, octyldiphenyl phosphate, diphenylbiphenylphosphate, trioctyl phosphate, tributyl phosphate, diethyl phthalate,dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutylphthalate, di-2-ethylhexyl phthalate, butylbenzyl phthalate, dibenzylphthalate, butyl phthalyl butyl glycolate, ethyl phthalyl ethylglycolate, methyl phthalyl ethyl glycolate, triethyl citrate,tri-n-butyl citrate, acetyltriethyl citrate, acetyl-tri-n-butyl citrate,and acetyl-tri-n-(2-ethylhexyl) citrate.

In another embodiment of the invention, the plasticizer can be one ormore esters comprising: (i) at least one acid residue including residuesof phthalic acid, adipic acid, trimellitic acid, succinic acid, benzoicacid, azelaic acid, terephthalic acid, isophthalic acid, butyric acid,glutaric acid, citric acid or phosphoric acid; and (ii) alcohol residuescomprising one or more residues of an aliphatic, cycloaliphatic, oraromatic alcohol containing up to about 20 carbon atoms.

In another embodiment of the invention, the plasticizer can be selectedfrom at least one of the following: esters comprising: (i) at least oneacid residue selected from the group consisting of phthalic acid, adipicacid, trimellitic acid, succinic acid, benzoic acid, azelaic acid,terephthalic acid, isophthalic acid, butyric acid, glutaric acid, citricacid and phosphoric acid; and (ii) at least one alcohol residue selectedfrom the group consisting of aliphatic, cycloaliphatic, and aromaticalcohol containing up to about 20 carbon atoms.

In another embodiment of the invention, the plasticizer can comprisealcohol residues where the alcohol residues is at least one selectedfrom the following: stearyl alcohol, lauryl alcohol, phenol, benzylalcohol, hydroquinone, catechol, resorcinol, ethylene glycol, neopentylglycol, 1,4-cyclohexanedimethanol, and diethylene glycol.

In another embodiment of the invention, the plasticizer can be selectedfrom at least one of the following: benzoates, phthalates, phosphates,arylene-bis(diaryl phosphate), and isophthalates. In another embodiment,the plasticizer comprises diethylene glycol dibenzoate, abbreviatedherein as “DEGDB”.

In another embodiment of the invention, the plasticizer can be selectedfrom at least one of the following: aliphatic polyesters comprisingC₂₋₁₀ diacid residues, for example, malonic acid, succinic acid,glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid,and sebacic acid; and C₂₋₁₀ diol residues.

In another embodiment, the plasticizer can comprise diol residues whichcan be residues of at least one of the following C₂-C₁₀ diols: ethyleneglycol, diethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol,1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, neopentylglycol, 1,5-pentanediol, 1,6 hexanediol, 1,5-pentylene glycol,triethylene glycol, and tetraethylene glycol.

In another embodiment of the invention, the plasticizer can includepolyglycols, such as, for example, polyethylene glycol, polypropyleneglycol, and polybutylene glycol. These can range from low molecularweight dimers and trimers to high molecular weight oligomers andpolymers. In one embodiment, the molecular weight of the polyglycol canrange from about 200 to about 2000.

In another embodiment of the invention, the plasticizer comprises atleast one of the following: Resoflex® R296 plasticizer, Resoflex® 804plastocizer, SHP (sorbitol hexapropionate), XPP(xylitolpentapropionate), XPA(xylitol pentaacetate), GPP(glucose pentaacetate),GPA (glucose pentapropionate) and APP (arabitol pentapropionate).

In another embodiment of the invention, the plasticizer comprises one ormore of: A) from about 5 to about 95 weight % of a C₂-C₁₂ carbohydrateorganic ester, wherein the carbohydrate comprises from about 1 to about3 monosaccharide units; and B) from about 5 to about 95 weight % of aC₂-C₁₂ polyol ester, wherein the polyol is derived from a C₅ or C₆carbohydrate. In one embodiment, the polyol ester does not comprise orcontain a polyol acetate or polyol acetates.

In another embodiment, the plasticizer comprises at least onecarbohydrate ester and the carbohydrate portion of the carbohydrateester is derived from one or more compounds selected from the groupconsisting of glucose, galactose, mannose, xylose, arabinose, lactose,fructose, sorbose, sucrose, cellobiose, cellotriose and raffinose.

In another embodiment of the invention, the plasticizer comprises atleast one carbohydrate ester and the carbohydrate portion of thecarbohydrate ester comprises one or more of α-glucose pentaacetate,β-glucose pentaacetate, α-glucose pentapropionate, β-glucosepentapropionate, α-glucose pentabutyrate and β-glucose pentabutyrate.

In another embodiment, the plasticizer comprises at least onecarbohydrate ester and the carbohydrate portion of the carbohydrateester comprises an α-anomer, a β-anomer or a mixture thereof.

In another embodiment of the invention, the plasticizer can be a solid,non-crystalline resin. These resins can contain some amount of aromaticor polar functionality and can lower the melt viscosity of the celluloseesters. In one embodiment of the invention, the plasticizer can be asolid, non-crystalline compound (resin), such as, for example, rosin;hydrogenated rosin; stabilized rosin, and their monofunctional alcoholesters or polyol esters; a modified rosin including, but not limited to,maleic- and phenol-modified rosins and their esters; terpene resins;phenol-modified terpene resins; coumarin-indene resins; phenolic resins;alkylphenol-acetylene resins; and phenol-formaldehyde resins.

In another embodiment of the invention, the plasticizer can be atackifier resin. Any tackifier known to a person of ordinary skill inthe art may be used in the cellulose ester/elastomer compositions.Tackifiers suitable for the compositions disclosed herein can be solids,semi-solids, or liquids at room temperature. Non-limiting examples oftackifiers include (1) natural and modified rosins (e.g., gum rosin,wood rosin, tall oil rosin, distilled rosin, hydrogenated rosin,dimerized rosin, and polymerized rosin); (2) glycerol andpentaerythritol esters of natural and modified rosins (e.g., theglycerol ester of pale, wood rosin, the glycerol ester of hydrogenatedrosin, the glycerol ester of polymerized rosin, the pentaerythritolester of hydrogenated rosin, and the phenolic-modified pentaerythritolester of rosin); (3) copolymers and terpolymers of natured terpenes(e.g., styrene/terpene and alpha methyl styrene/terpene); (4)polyterpene resins and hydrogenated polyterpene resins; (5) phenolicmodified terpene resins and hydrogenated derivatives thereof (e.g., theresin product resulting from the condensation, in an acidic medium, of abicyclic terpene and a phenol); (6) aliphatic or cycloaliphatichydrocarbon resins and the hydrogenated derivatives thereof (e.g.,resins resulting from the polymerization of monomers consistingprimarily of olefins and diolefins); (7) aromatic hydrocarbon resins andthe hydrogenated derivatives thereof; and (8) aromatic modifiedaliphatic or cycloaliphatic hydrocarbon resins and the hydrogenatedderivatives thereof; and combinations thereof.

In another embodiment of the invention, the tackifier resins includerosin-based tackifiers (e.g. AQUATAC® 9027, AQUATAC® 4188, SYLVALITE®,SYLVATAC® and SYL V AGUM® rosin esters from Arizona Chemical,Jacksonville, Fla.). In other embodiments, the tackifiers includepolyterpenes or terpene resins (e.g., SYLVARES® 15 terpene resins fromArizona Chemical, Jacksonville, Fla.). In other embodiments, thetackifiers include aliphatic hydrocarbon resins such as resins resultingfrom the polymerization of monomers consisting of olefins and diolefins(e.g., ESCOREZ® 1310LC, ESCOREZ® 2596 from ExxonMobil Chemical Company,Houston, Tex. or PICCOTAC® 1095 from Eastman Chemical Company,Kingsport, Tenn.) and the hydrogenated derivatives 20 thereof; alicyclicpetroleum hydrocarbon resins and the hydrogenated derivatives thereof(e.g. ESCOREZ® 5300 and 5400 series from ExxonMobil Chemical Company;EASTOTAC® resins from Eastman Chemical Company). In some embodiments,the tackifiers include hydrogenated cyclic hydrocarbon resins (e.g.REGALREZ® and REGALITE® resins from Eastman Chemical Company). Infurther embodiments, the tackifiers are modified with tackifiermodifiers including aromatic compounds (e.g., ESCOREZ® 2596 fromExxonMobil Chemical Company or PICCOTAC® 7590 from Eastman ChemicalCompany) and low softening point resins (e.g., AQUATAC 5527 from ArizonaChemical, Jacksonville, Fla.). In some embodiments, the tackifier is analiphatic hydrocarbon resin having at least five carbon atoms.

The amount of plasticizer in the cellulose ester composition can rangefrom about 1 to about 50 weight percent based on the weight of thecellulose ester. Another range can be from about 5 to about 35 weightpercent based on the weight of the cellulose ester.

The compatibilizer can be either a non-reactive compatibilizer or areactive compatibilizer. The compatibilizer can enhance the ability ofthe cellulose ester to reach a desired small particle size to improvethe dispersion of the cellulose ester into an elastomer. Thecompatibilizers used can also improve mechanical and physical propertiesof the cellulose ester/elastomer compositions by improving theinterfacial interaction/bonding between the cellulose ester and theelastomer.

When non-reactive compatibilizers are utilized, the compatibilizercontains a first segment that is compatible with the cellulose ester anda second segment that is compatible with a nonpolar elastomer. The firstsegment contains polar functional groups, which provide compatibilitywith the cellulose ester, including, but not limited to, such polarfunctional groups as ethers, esters, amides, alcohols, amines, ketonesand acetals. The first segment may consist of oligomers or polymers ofthe following: cellulose esters; cellulose ethers; polyoxyalkylene, suchas, polyoxyethylene, polyoxypropylene, polyoxybutylene; polyglycols,such as, polyethylene glycol, polypropylene glycol, polybutylene glycol;polyesters, such as, polycaprolactone, polylactic acid, aliphaticpolyesters, aliphatic-aromatic copolyesters; polyacrylates andpolymethacrylates; polyacetals; polyvinylpyrrolidone; polyvinyl acetate;and polyvinyl alcohol. In one embodiment, the first segment ispolyoxyethylene or polyvinyl alcohol.

The second segment is compatible with the nonpolar elastomer andcontains nonpolar groups. The second segment can be either saturated orunsaturated hydrocarbon groups or contain both saturated and unsaturatedhydrocarbon groups. The second segment can be an oligomer or a polymer.In one embodiment of the invention, the second segment of thenon-reactive compatibilizer is selected from the group consisting ofpolyolefins, polydienes, polyaromatics, and copolymers. An example of apolyaromatic second segment is polystyrene. An example of a copolymersecond segment is styrene/butadiene copolymer.

In one embodiment, the first and second segments of the non-reactivecompatibilizers can be in a diblock, triblock, branched or combstructure. The molecular weight of the non-reactive compatibilizers canrange from about 300 to about 20,000 or from about 500 to about 10,000or from about 1,000 to about 5,000. The segment ratio of thenon-reactive compatibilizers can range from about 15 to about 85% polarfirst segments to about 15 to about 85% nonpolar second segments.

Examples of non-reactive compatibilizers include, but are not limitedto, ethoxylated alcohols, ethoxylated alkylphenols, ethoxylated fattyacids, block polymers of propylene oxide and ethylene oxide,polyglycerol esters, polysaccharide esters, and sorbitan esters.Examples of ethoxylated alcohols are C₁₁-C₁₅ secondary alcoholethoxylates, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether,and C₁₂-C₁₄ natural liner alcohol ethoxylated with ethylene oxide.C₁₁-C₁₅ secondary ethyoxylates can be obtained as Dow Tergitol® 15S fromthe Dow Chemical Company. Polyoxyethlene cetyl ether and polyoxyethylenestearyl ether can be obtained from ICI Surfactants under the Brij®series of products. C₁₂-C₁₄ natural linear alcohol ethoxylated withethylene oxide can be obtained from Hoechst Celanese under the Genapol®series of products. Examples of ethoxylated alkylphenols includeoctylphenoxy poly(ethyleneoxy)ethanol and nonylphenoxypoly(ethyleneoxy)ethanol. Octylphenoxy poly(ethyleneoxy)ethanol can beobtained as Igepal® CA series of products from Rhodia, and nonylphenoxypoly(ethyleneoxy)ethanol can be obtained as Igepal CO series of productsfrom Rhodia or as Tergitol® NP from Dow Chemical Company. Ethyoxylatedfatty acids include polyethyleneglycol monostearate or monolaruate whichcan be obtained from Henkel under the Nopalcol® series of products.Block polymers of propylene oxide and ethylene oxide can be obtainedunder the Pluronic® series of products from BASF. Polyglycerol esterscan be obtained from Stepan under the Drewpol® series of products.Polysaccharide esters can be obtained from Henkel under the Glucopon®series of products, which are alkyl polyglucosides. Sorbitan esters canbe obtained from ICI under the Tween® series of products.

In another embodiment of the invention, the non-reactive compatibilizerscan be synthesized in situ in the cellulose ester composition or thecellulose ester/elastomer composition by reacting celluloseester-compatible compounds with elastomer-compatible compounds. Thesecompounds can be, for example, telechelic oligomers, which are definedas prepolymers capable of entering into further polymerization or otherreaction through their reactive end groups. In one embodiment of theinvention, these in situ compatibilizers can have higher molecularweight from about 10,000 to about 1,000,000.

In another embodiment of the invention, the compatibilizer can bereactive. The reactive compatibilizer comprises a polymer or oligomercompatible with one component of the composition and functionalitycapable of reacting with another component of the composition. There aretwo types of reactive compatibilizers. The first reactive compatibilizerhas a hydrocarbon chain that is compatible with a nonpolar elastomer andalso has functionality capable of reacting with the cellulose ester.Such functional groups include, but are not limited to, carboxylicacids, anhydrides, acid chlorides, epoxides, and isocyanates. Specificexamples of this type of reactive compatibilizer include, but are notlimited to: long chain fatty acids, such as, stearic acid (octadecanoicacid); long chain fatty acid chlorides, such as, stearoyl chloride(octadecanoyl chloride); long chain fatty acid anhydrides, such as,stearic anhydride (octadecanoic anhydride); epoxidized oils and fattyesters; styrene maleic anhydride copolymers; maleic anhydride graftedpolypropylene; copolymers of maleic anhydride with olefins and/oracrylic esters, e.g. terpolymers of ethylene, acrylic ester and maleicanhydride; and copolymers of glycidyl methacrylate with olefins and/oracrylic esters, e.g. terpolymers of ethylene, acrylic ester, andglycidyl methacrylate.

Reactive compatibilizers can be obtained as SMA® 3000 styrene maleicanhydride copolymer from Sartomer/Cray Valley, Eastman G-3015® maleicanhydride grafted polypropylene from Eastman Chemical Company, Epolene®E-43 maleic anhydride grafted polypropylene obtained from WestlakeChemical, Lotader® MAH 8200 random terpolymer of ethylene, acrylicester, and maleic anhydride obtained from Arkema, Lotader® GMA AX 8900random terpolymer of ethylene, acrylic ester, and glycidyl methacrylate,and Lotarder® GMA AX 8840 random terpolymer of ethylene, acrylic ester,and glycidyl methacrylate.

The second type of reactive compatibilizer has a polar chain that iscompatible with the cellulose ester and also has functionality capableof reacting with a nonpolar elastomer. Examples of these types ofreactive compatibilizers include cellulose esters or polyethyleneglycols with olefin or thiol functionality. Reactive polyethylene glycolcompatibilizers with olefin functionality include, but are not limitedto, polyethylene glycol allyl ether and polyethylene glycol acrylate. Anexample of a reactive polyethylene glycol compatibilizer with thiolfunctionality includes polyethylene glycol thiol. An example of areactive cellulose ester compatibilizer includes mercaptoacetatecellulose ester.

The amount of compatibilizer in the cellulose ester composition canrange from about 1 wt % to about 40 wt % or from about 5 wt % to about20 wt % based on the weight of the cellulose ester.

In another embodiment of this invention, a cellulose ester/elastomercomposition is provided comprising at least one elastomer, at least onecellulose ester, and at least one additive; wherein the additive is atleast one selected from the group consisting of at least one plasticizerand at least one compatibilizer. The cellulose esters, plasticizers, andcompatibilizers have been previously described in this disclosure.

The term “elastomer,” as used herein, can be used interchangeably withthe term “rubber.” Due to the wide applicability of the processdescribed herein, the cellulose esters can be employed with virtuallyany type of elastomer. For instance, the elastomers utilized in thisinvention can comprise a natural rubber, a modified natural rubber, asynthetic rubber, and mixtures thereof.

In certain embodiments of the present invention, at least one of theelastomers is a non-polar elastomer. For example, a non-polar elastomercan comprise at least about 90, 95, 98, 99, or 99.9 weight percent ofnon-polar monomers. In one embodiment, the non-polar elastomer isprimarily based on a hydrocarbon. Examples of non-polar elastomersinclude, but are not limited to, natural rubber, polybutadiene rubber,polyisoprene rubber, butyl rubber, styrene-butadiene rubber,polyolefins, ethylene propylene monomer rubber (EPM), ethylene propylenediene monomer (EPDM) rubber, and polynorbornene rubber. Examples ofpolyolefins include, but are not limited to, polybutylene,polyisobutylene, and ethylene propylene rubber. In another embodiment,the elastomer comprises a natural rubber, a styrene-butadiene rubber,and/or a polybutadiene rubber. Non-polar elastomers are often used intire components.

In certain embodiments, the elastomer contains little or no nitrilegroups. As used herein, the elastomer is considered a “non-nitrile”elastomer when nitrile monomers make up less than 10 weight percent ofthe elastomer. In one embodiment, the elastomer contains no nitrilegroups.

These inventive cellulose ester/elastomer compositions can be utilizedin various articles, including oil field elastomeric articles, weatherstripping, and injected molded parts. Any elastomer known in the art foruse in these articles can utilized. When the cellulose ester/elastomercompositions are used in oil field elastomeric articles, the elastomerscan be nitrile rubber, fluorocarbon rubber, chlorinated sulfonatedpolyethylene, polychloroprene, and mixtures thereof. When the celluloseester/elastomer compositions are used in weather stripping, theelastomer can be natural rubber, polybutadiene rubber, polyisoprenerubber, butyl rubber, styrene-butadiene rubber, polyolefins, ethylenepropylene monomer rubber (EPM), ethylene propylene diene monomer (EPDM)rubber, polynorbornene rubber, and mixtures thereof. When the celluloseester/elastomer compositions are used in injected molder parts, theelastomer can be natural rubber, polybutadiene rubber, polyisoprenerubber, butyl rubber, styrene-butadiene rubber, polyolefins, ethylenepropylene monomer rubber (EPM), ethylene propylene diene monomer (EPDM)rubber, polynorbornene rubber, and methyl methacrylate butadiene styrenerubber (MBS), styrene butadiene styrene rubber (SBS), styrene ethylenebutylene (SEBS) rubber, silicone rubber, urethane rubber, and mixturesthereof.

The amount of cellulose ester in the cellulose ester/elastomercomposition ranges from about 1 to about 50 parts per hundred rubber(phr) based on the elastomer. Other ranges are from about 5 to about 30phr and about 3 to about 30 phr based on the weight of the elastomer.

In another embodiment of the present invention, the celluloseester/elastomer composition can comprise at least about 1, 2, 3, 4, 5,or 10 parts per hundred rubber (“phr”) of at least one cellulose ester,based on the total weight of the elastomers. Additionally oralternatively, the cellulose ester/elastomer composition of the presentinvention can comprise not more than about 75, 50, 40, 30, or 20 phr ofat least one cellulose ester, based on the total weight of theelastomers. The term “phr,” as used herein, refers to parts of arespective material per 100 parts by weight of rubber or elastomer.

The amount of compatibilizer can range from about 1% to about 40% byweight based on the weight of the cellulose ester. Another range is fromabout 5 to about 20% by weight based on the weight of the celluloseester.

In another embodiment of the invention, the compatibilizer can compriseat least about 1, 2, 3, or 5 weight percent based on the weight of thecellulose ester. Additionally or alternatively, the compatibilizer cancomprise not more than about 40, 30, 25, or 20 weight percent based theweight of the cellulose ester.

The amount of plasticizer can range from about 1% to about 50% by weightbased on the weight of the cellulose ester. Another range is from about5% to about 35% by weight based on the weight of the cellulose ester.

In another embodiment of the invention, the amount of plasticizer canrange from at least about 1, 2, 5, or 10 weight percent based on theweight of the cellulose ester. Additionally or alternatively, theplasticizer can range from not more than about 60, 50, 40, or 35 weightpercent based on the cellulose ester.

In another embodiment of the invention, the cellulose ester/elastomercompositions further comprise at least one crosslinking/curing agent.Crosslinking/curing agents can be any that is known in the art. Examplesof crosslinking/curing agents include, but are not limited to, organicperoxides and sulfur.

The cellulose ester/elastomer compositions of the present invention canbe incorporated into various types of end products.

In certain embodiments, the cellulose ester/elastomer composition isformed into a tire and/or a tire component. The tire component cancomprise, for example, tire tread, subtread, undertread, body plies,belts, overlay cap plies, belt wedges, shoulder inserts, tire apex, tiresidewalls, bead fillers, and any other tire component that contains anelastomer. In one embodiment, the cellulose ester/elastomer compositionis formed into tire tread, tire sidewalls, and/or bead fillers.

In certain embodiments, the cellulose ester/elastomer composition isincorporated into non-tire applications. Non-tire applications include,for example, a blow-out preventer, fire hoses, weather stripping, belts,injection molded parts, footwear, pharmaceutical closures, plant lining,flooring, power cables, gaskets, seals, and architectural trims. Inparticular, the cellulose ester/elastomer compositions can be utilizedin various oil field applications such as, for example, blowoutpreventers, pump pistons, well head seals, valve seals, drilling hoses,pump stators, drill pipe protectors, down-hole packers, inflatablepackers, drill motors, O-Rings, cable jackets, pressure accumulators,swab cups, and bonded seals.

In one embodiment, the tire component comprises at least one elastomer,at least one filler, the cellulose ester/elastomer composition, andoptionally starch. The elastomer and cellulose ester composition havebeen previously discussed in this disclosure.

In certain embodiments, the cellulose ester/elastomer composition of thepresent invention can comprise one or more fillers, particularly in theproduction of tire components.

The fillers can comprise any filler that can improve the thermophysicalproperties of the cellulose ester/elastomer composition (e.g., modulus,strength, and expansion coefficient). For example, the fillers cancomprise silica, carbon black, clay, alumina, talc, mica, discontinuousfibers including cellulose fibers and glass fibers, aluminum silicate,aluminum trihydrate, barites, feldspar, nepheline, antimony oxide,calcium carbonate, kaolin, and combinations thereof. In one embodiment,the fillers comprise an inorganic and nonpolymeric material. In anotherembodiment, the fillers comprise silica and/or carbon black. In yetanother embodiment, the fillers comprise silica.

In certain embodiments, the cellulose ester/elastomer composition cancomprise at least about 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50 phr ofone or more fillers, based on the total weight of the elastomers.Additionally or alternatively, the cellulose ester/elastomer compositioncan comprise not more than about 60, 50, or 40 phr of one or morefillers, based on the total weight of the elastomers.

The cellulose ester/elastomer composition of the present invention cancomprise one or more additives.

In certain embodiments, the cellulose ester/elastomer composition cancomprise at least about 1, 2, 5, 10, or 15 phr of one or more additives,based on the total weight of the elastomers. Additionally oralternatively, the cellulose ester/elastomer composition can comprisenot more than about 70, 50, 40, 30, or 20 phr of one or more additives,based on the total weight of the elastomers.

The additives can comprise, for example, processing aids, carrierelastomers, tackifiers, lubricants, oils, waxes, surfactants,stabilizers, UV absorbers/inhibitors, pigments, antioxidants, extenders,reactive coupling agents, and/or branchers. In one embodiment, theadditives comprise one or more cellulose ethers, starches, and/orderivatives thereof. In such an embodiment, the cellulose ethers,starches and/or derivatives thereof can include, for example, amylose,acetoxypropyl cellulose, amylose triacetate, amylose tributyrate,amylose tricabanilate, amylose tripropionate, carboxymethyl amylose,ethyl cellulose, ethyl hydroxyethyl cellulose, hydroxyethyl cellulose,methyl cellulose, sodium carboxymethyl cellulose, and sodium cellulosexanthanate.

In one embodiment, the additives comprise a non-cellulose esterprocessing aid. The non-cellulose ester processing aid can comprise, forexample, a processing oil, starch, starch derivatives, and/or water. Insuch an embodiment, the cellulose ester/elastomer composition cancomprise less than about 10, 5, 3, or 1 phr of the non-cellulose esterprocessing aid, based on the total weight of the elastomers.Additionally or alternatively, the cellulose ester/elastomer compositioncan exhibit a weight ratio of cellulose ester to non-cellulose esterprocessing aid of at least about 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 8:1, or10:1.

In another embodiment, the cellulose ester/elastomer composition cancomprise a starch and/or its derivatives. In such an embodiment, thecellulose ester/elastomer composition can comprise less than 10, 5, 3,or 1 phr of starch and its derivatives, based on the total weight of theelastomers. Additionally or alternatively, the cellulose ester/elastomercomposition can exhibit a weight ratio of cellulose ester to starch ofat least about 3:1, 4:1, 5:1, 8:1, or 10:1.

In another embodiment of the invention, a process for producing acellulose ester composition is provided. The process comprisescontacting at least one cellulose ester, at least one compatibilizer,and optionally, at least one plasticizer. The cellulose ester,plasticizer, and compatibilizer were previously discussed in thisdisclosure. The cellulose ester, compatibilizer, and optionalplasticizer can be mixed in any order of addition.

In another embodiment of this invention, a process for producing acellulose ester/elastomer composition is provided comprising: a) mixingat least one elastomer, at least one cellulose ester, and at least oneadditive for a sufficient time and temperature to disperse the celluloseester to produce the cellulose ester/elastomer composition; wherein theadditive is at least one selected from the group consisting of acompatibilizer and a plasticizer. A sufficient temperature is defined asthe flow temperature of the cellulose ester which is generally about 50°C. above the Tg of the cellulose ester. The temperature at mixing islimited at the upper range by the processing temperature of theelastomer and at the lower range by the highest use temperature of thecellulose ester/elastomer composition.

It is known in the art that the efficiency of mixing two or moreviscoelastic materials can depend on the ratio of the viscosities of theviscoelastic materials. For a given mixing equipment and shear raterange, the viscosity ratio of the dispersed phase (cellulose ester andadditive) and continuous phase (elastomer) should be within specifiedlimits for obtaining adequate particle size. In one embodiment of theinvention where low shear rotational shearing equipment is utilized,such as, Banbury and Brabender mixers, the viscosity ratio of thedispersed phase (cellulose ester and additive) to the continuous phase(elastomer) can range from about 0.001 to about 5, from about 0.01 toabout 5, and from about 0.1 to about 3. In yet another embodiment of theinvention where high shear rotational/extensional shearing equipment isutilized, such as, twin screw extruders, the viscosity ratio of thedispersed phase (cellulose ester and additive) to the continuous phase(elastomer) can range from about 0.001 to about 500 and from about 0.01to about 100.

It is also known in the art that when mixing two or more viscoelasticmaterials, the difference between the interfacial energy of the twoviscoelastic materials can affect the efficiency of mixing. Mixing canbe more efficient when the difference in the interfacial energy betweenthe materials are less. In one embodiment of the invention, the surfacetension difference between the dispersed phase (cellulose ester andadditive) and continuous phase (elastomer) is less than about 100dynes/cm, less than 50 dynes/cm, or less than 20 dynes/cm.

In one embodiment, the cellulose ester is softened and/or melted toallow breakdown of the cellulose ester into sufficiently small particlesize under the specified mixing conditions. In one embodiment, theparticle size of the cellulose ester can be between 50 microns to 50nanometers. In one embodiment of the invention, the elastomer, at leastone cellulose ester, and at least one additive are contacted at atemperature in the range of about 70° C. to about 220° C. or from about100° C. to about 180° C., or from about 130° C. to about 160° C.

Mixing of the elastomer, cellulose ester, and additive can beaccomplished by any method known in the art that is adequate to dispersethe additive. Examples of mixing equipment include, but are not limitedto, Banbury mixers, Brabender mixers, and extruders (single or twinscrew). The shear energy during the mixing is dependent on thecombination of equipment, blade design, rotation speed (rpm), and mixingtime. The shear energy should be sufficient for breaking downsoftened/melted cellulose ester to a small enough size to disperse thecellulose ester throughout the elastomer. For example, when a Banburymixer is utilized, the shear energy and time of mixing ranges from about5 to about 15 minutes at 100 rpms.

The elastomer, cellulose ester and additive can be combined in any orderduring the process. In one embodiment, the cellulose ester is premixedwith the compatibilizer and/or the plasticizer. The cellulose estercontaining the compatibilizer and/or the plasticizer is then mixed withthe elastomer. In another embodiment of the invention, when reactivecompatibilizers are utilized, the reactive compatibilizers can be mixedwith either the cellulose ester or the elastomer first, then the othercomponents are added.

In another embodiment of the invention, a process to produce a celluloseester/elastomer compositions comprising: a) mixing at least oneelastomer, at least one cellulose ester and at least one additive for asufficient time and temperature to disperse the cellulose esterthroughout said elastomer to produce a cellulose ester/elastomermasterbatch; wherein the additive is at least one selected from thegroup consisting of a compatibilizer and a plasticizer; and b) mixingthe masterbatch and at least one elastomer to produce the celluloseester/elastomer composition. The elastomer in the masterbatch can be thesame or different than that utilized to produce the celluloseester/elastomer composition. The processes of mixing have beenpreviously discussed in this disclosure.

This invention can be further illustrated by the following examples ofpreferred embodiments thereof, although it will be understood that theseexamples are included merely for purposes of illustration and are notintended to limit the scope of the invention unless otherwisespecifically indicated.

EXAMPLES Example 1 Non-Reactive Compatibilizer in CelluloseEster/Elastomer Compositions

Experiments were conducted to evaluate certain non-reactivecompatibilizer in cellulose ester/elastomer compositions. In Table 1,the non-reactive compatibilizers evaluated are listed.

TABLE 1 Compatibilizer Compound MW¹ #CH₂ ² #EO³ % EO MP⁴ ° C. Tergitol ®15-S-9 570 15 9 63 <RT Tergitol ® 15-S-30 1400 15 30 85 ~50 Polyethylene920 32 12 50 ~100 block polyethylene glycol⁵ Polyethylene 2250 32 40 80~85 block polyethylene glycol Polyethylene 1400 50 16 50 ~100 blockpolyethylene glycol ¹Molecular Weight ²Number of carbon atoms ³Number ofEthylene Oxide groups ⁴Melting Point ⁵PE Block PEG

Tergitol® 15-S-9 and Tergitol® 15-S-30 are secondary alcohol ethoxylatesobtained from Dow Chemical in Midland, Mich. The polyethylene blockpolyethylene glycol compatibilizers were obtained from Sigma-Aldrich.Although not wishing to be bound by theory, it is believed that theethylene oxide units of the above compounds plasticizes the celluloseacetate butyrate and the hydrocarbon chain improves compatibility withthe elastomer. Each of the compatibilizers was blended with celluloseacetate butyrate (CAB 551-0.01 and CAB 553.0.4) obtained from EastmanChemical Company, Kingsport, Tenn. at 80:20 ratio in a Brabender mixerat 150° C. for 10 minutes at 100 rpm) followed by cryogrinding toprepare the masterbatches of cellulose ester and compatibilizer (MB1-10) as shown in Table 2.

TABLE 2 CAB CAB PE PE PE Master 551- 553- Tergitol Tergitol Block BlockBlock Batch 0.01 0.4 15-S-9 15-S-30 PEG PEG PEG Tg, ° C. MB1 80 20 49.3MB2 80 20 52.6 MB3 80 20 54.3 MB4 80 20 66.6 MB5 80 20 97.5 MB6 80 2082.3 MB7 80 20 75.8 MB8 80 20 84.2 MB9 80 20 69.5 MB10 80 20 104.7Reference Tg for CAB 551-0.01 is 107° C. and for CAB 553-0.4 is 139° C.

All the above master batches of cellulose ester and compatibilizer arecompounded with a non-oil modified solution styrene-butadiene rubberobtained as Duradene 761 from Firestone Polymers, Akron, Ohio, using theprocedure outlined subsequently in these Examples to prepare samplecompositions shown in Table 3.

TABLE 3 Comp Duradene CAB CAB No. 761 551-0.01 553-0.4 MB1 MB2 MB3 MB4MB5 MB6 MB7 MB8 MB9 MB10 1.1 100 1.2 100 10 1.3 100 12.5 1.4 100 12.51.5 100 12.5 1.6 100 12.5 1.7 100 12.5 1.8 100 10 1.9 100 12.5 1.10 10012.5 1.11 100 12.5 1.12 100 12.5 1.13 100 12.5

The amounts specified in Table 3 are based on 100 grams of rubber andexpressed as parts per hundred rubber (phr). For example, forComposition 1.3, 100 grams of rubber was utilized as well as 12.5 gramsof Masterbatch 1, which is an 80:20 ratio of cellulose acetate butyrate(CAB 553-0.4) and Tergitol 15-S-9 secondary alcohol ethoxylate.

All cellulose ester, elastomer, and compatibilizers in Table 3 wereprocessed in a Brabender mixer for 30 minutes at 150° C. and 100 rpm toproduce the cellulose ester/elastomer composition. Then, 2.5 phr dicumylperoxide (curing agent) was added to each sample at 50-60° C. in aBrabender mixer for about 1 minute and then mixed for another 2-3minutes to produce a partially cured cellulose ester/elastomercomposition. The samples from the Brabender mixer were cured bycompression molding for 45 minutes at 150° C. and 20000 psi.

The modulus, yield stress, and yield strain of the compression molded,cured cellulose ester/elastomer composition samples were measured as perASTM D412 and are shown in Table 4. In the ASTM D412 method, sampleswere prepared by cutting the specimens with Die C. The speed of testingwas 20 inches/min, and the gauge length was 63.5 mm (2.5 inch). Thesamples were conditioned in the laboratory for 40 hours at 50%+/−5%humidity and 72° F. The width of the specimen was 1 inch and the lengthwas 4.5 inches.

TABLE 4 Composition Modulus, Yield Stress, Yield Strain, Number MPa MPa% 1.1 6.99 1.37 22.11 1.2 7.75 1.66 22.44 1.3 8.29 1.67 24.41 1.4 8.611.91 26.67 1.5 7.87 1.86 28.23 1.6 9.57 2.03 26.76 1.7 9.53 1.98 24.731.8 10.77 1.27 12.93 1.9 10.14 1.45 16.8 1.10 7.46 1.62 25.88 1.11 6.441.16 21.42 1.12 9.08 1.53 20.02 1.13 10.61 1.63 17.33

In Compositions 1.3-1.7, the addition of the compatibilizer to theelastomer and cellulose ester showed an improvement in modulus, yieldstress, and yield strain over the Comparative Compositions 1.1 and 1.2containing either rubber alone or rubber and cellulose ester alone. InCompositions 1.9-1.13, the Yield Strain and Yield Stress were improvedover the Comparative Composition 1.8.

Example 2 Reactive Compatabilizers in Cellulose Ester/ElastomerCompositions

Reactive compatibilizers were evaluated to improve the mixing of CAB instyrene butadiene rubber (SBR). The reactive compatibilizers wereselected such that they contained reactive groups that can react withthe CAB and the rest of the molecule is compatible with the SBR. Themolecular weight, and the type and concentration of the reactive moietywere varied.

TABLE 5 Chemical Reactive Acid number, Brand Name CompositionManufacturer Moiety Mw mg KOH/gm Tm, ° C. Comments SMA 3000 Styrenemaleic Sartomer/Cray Maleic 9500 285 180 (Tm ~ Styrene: anhydridecopolymer Valley anhydride Tg + 55) MA = 3:1 Eastman Maleic anhydrideEastman Maleic 47000 15 156 G-3015 grafted polypropylene anhydrideEpolene ® E-43 Maleic anhydride Westlake Maleic 15800 45 158 graftedpolypropylene Chemicals anhydride Lotader ® MAH Random terpolymer ofArkema Maleic 17 100 Maleic anhy- 8200 Ethylene, Acrylic ester anhydridedride ~2.8 wt % and Maleic anhydride Ester ~6.5 wt % Lotader ® GMARandom terpolymer of Arkema Glycidyl NA  65 Glycidyl Meth- AX 8900Ethylene, Acrylic ester Methacrylate acrylate ~8 wt %, and glycidylMethacrylate (epoxy) Ester ~25 wt % Lotader ® GMA Random terpolymer ofArkema Glycidyl NA 106 Glycidyl Meth- AX 8840 Ethylene, Acrylic esterMethacrylate acrylate ~8 wt %, and glycidyl Methacrylate (epoxy) Ester~0 wt %

The maleic anhydride and glycidyl methacrylate in these reactivecompatibilizers can react with the hydroxyl group contained in thecellulose ester. Masterbatches of Duradene 761 styrene butadiene rubberand a reactive compatibilizer were produced as shown in Table 6.Duradene 761 styrene butadiene rubber and the reactive compatibilizerwere mixed in a Brabender mixer at 100 rpm and 160° C. for 30 minutes toproduce the masterbatches (MB1-MB6).

TABLE 6 Composition Duradene Compatibilizer No. 761, gm Compatibilizerquantity, gm MB1 100 SMA 3000 3 MB2 100 Eastman G-3015 3 MB3 100Epolene ® E-43 3 MB4 100 Lotader ® MAH 8200 3 MB5 100 Lotader ® GMA AX8900 3 MB6 100 Lotader ® GMA AX 8840 3

The cellulose ester/elastomer compositions produced are shown in Table7. Composition Number 2.1 contained only SBR. Composition Number 2.2contained only SBR and CAB 551-0.01. For Composition Numbers 2.3-2.8,the masterbatches produced containing SBR and compatibilizer were mixedwith cellulose ester in a Brabender mixer at 100 rpm for 30 minutes at150° C.

A CAB/plasticizer masterbatch was prepared by blending 100 g CAB 553-0.4and 10 g Eastman 168 plasticizer(bis(2-ethylhexyl)-1,4-benzenedicarboxylate) obtained from EastmanChemical Company using a Brabender mixer at 100 rpm and 150° C. for 10minutes. The CAB/plasticizer masterbatch was cryo-ground to a powder.Eastman 168 plasticizer was added to reduce the Tg/Tm of the CAB 553-0.4so that it melted at a processing temperature of about 150° C. The Tg ofthe CAB/plasticizer masterbatch was obtained by preparing samplesdissolved in acetone followed by vacuum drying at 70° C. and analyzingthe samples by Differential Scanning calorimetry (DSC) (2nd cycle). OnlyCAB 553-0.4 was utilized in the masterbatches. CAB 551-0.01 was mixedwith Eastman 168 plasticizer to determine the Tg. The glass transitiontemperatures (Tg) of the cellulose ester/plasticizer compositionsproduced are shown in Table 8.

TABLE 7 Composition Duradene CAB MB (CAB/ Number 761 551-0.01Plasticizer) MB1 MB2 MB3 MB4 MB5 MB6 2.1 100 2.2 100 10 2.3 10 103 2.410 103 2.5 10 103 2.6 10 103 2.7 10 103 2.8 10 103 2.9 100 11 2.10 11103 2.11 11 103 2.12 11 103 2.13 11 103 2.14 11 103 2.15 11 103

TABLE 8 Plasticizer wt % Tg, ° C. CAB 551-0.01 (10 g) + Plasticizer 168(0.5 g) 5 90.5 CAB 551-0.01 (10 g) + Plasticizer 168 (1.0 g) 10 75.5 CAB553-0.4 (10 g) + Plasticizer 168 (0.5 g) 5 123.7 CAB 553-0.4 (10 g) +Plasticizer 168 (1.0 g) 10 109.5

Once the masterbatches were prepared, the CAB 551-0.01 and theCAB/Plasticizer Masterbatch were dried overnight at 50° C. to removemoisture before blending. Composition Numbers 2.1-2.15 were prepared byweighing each component in Table 6 separately and processing thecomponents in a Brabender mixed at 100 rpm for 30 minutes at 150° C. Inorder to cure the cellulose ester/elastomer composition, 1 g of dicumylperoxide (i.e. 2.5 phr) was added to the Brabender mixer over a periodof about 1 minute and then the composition was further mixed for another2-3 minutes to produce a partially cured cellulose ester/elastomercomposition. The curing of the cellulose ester/elastomer composition wasthen completed by compression molding for 45 minutes at 150° C. and20000 psi.

The modulus, yield stress and yield strain of the compression moldedcured samples were measured as per ASTM D412 and are shown in Table 9.

TABLE 9 Composition Modulus, Yield Stress, Yield Strain, Number MPa MPa% 2.1 6.99 1.37 22.11 2.2 7.66 1.45 21.66 2.3 14.08 2.01 18.05 2.4 10.551.73 17.62 2.5 7.01 1.45 23.27 2.6 14.65 1.79 13.66 2.7 9.89 1.69 20.002.8 11.36 2.2 22.62 2.9 10.48 1.39 14.52 2.10 11.82 1.69 15.23 2.11 9.891.72 18.68 2.12 8.92 1.68 20.49 2.13 8.95 1.53 18.49 2.14 6.82 1.3223.19 2.15 7.35 1.56 25.23

These data show that the addition of CAB 551-0.01 to a masterbatch ofrubber and a reactive compatibilizer in Compositions 2.3-2.8 showed anincrease in modulus over Comparative Composition 2.1 with rubber aloneor Composition 2.2 with rubber and CAB 551-0.01. Yield Strain and tosome extent Yield Stress was also improved in Compositions 2.10-2.15 incomparison to Composition 2.9 when the CAB/Plasticizer masterbatch wasadded to the SBR/Compatibilizer masterbatch.

Example 3 Use of Plasticizers

Masterbatches of cellulose esters with two different plasticizers atvarious loadings were prepared in an attempt to lower the Tg of thecellulose esters such that their flow temperature is lower than thetypical rubber processing temperature of 150° C. Compounding in aBrabender mixer at 150° C. for 10 minutes at 100 rpm followed bycryogrinding yielded the masterbatches shown in Table 10.

TABLE 10 Tg of Master Tg of Quantity Type of Quantity of master BatchCE¹ CE, ° C. of CE, g Plasticizer plasticizer, g Batch, ° C. MB1 CAB551-0.2 101 100 Eastman 168² 10 84 MB2 CAB 553-0.4 136 100 Eastman 16825 85 MB3 CAB 381-0.1 123 100 Eastman 168 20 87 MB4 CAB 381-2 133 100Eastman 168 25 95 MB5 CAB 553-0.4 136 100 Poly (ethylene 25 65 glycol)³MB6 CAB 381-2 133 100 Poly (ethylene 25 70 glycol) MB7 CAP 504-0.2 159100 Poly (ethylene 30 93 glycol) MB8 CAP 482-0.5 142 100 Poly (ethylene25 90 glycol) MB9 CA 398-3 180 100 Poly (ethylene 40 109 glycol)¹CE—Cellulose Ester ²bis(2-ethylhexyl)-1,4-benzene dicarboxylate³polyethylene glycol—molecular weight 300—from Aldrich

All the above masterbatches were compounded with styrene butadienerubber (SBR). The SBR and the masterbatch were mixed in a Brabendermixer for 30 minutes at 150° C. and 100 rpm. 2.5 phr dicumyl peroxide(curing agent) were added to each sample at 50-60° C. in the Brabendermixer in 1 minute and then mixed for another 2-3 minutes. The samplesfrom the Brabender mixer were compression molded for 45 minutes at 150°C. and 20000 psi. The formulation of these samples are shown in Table11. Each cellulose ester containing masterbatch sample has 10 phr (partsper hundred rubber) cellulose ester.

TABLE 11 Composition No. CE CE Quantity, g Duradene 761, g 3.1 None 1003.2 MB1 11 100 3.3 MB2 12.5 100 3.4 MB3 12 100 3.5 MB4 12.5 100 3.6 MB512.5 100 3.7 MB6 12.5 100 3.8 MB7 13 100 3.9 MB8 12.5 100 3.10 MB9 14100

The modulus, yield stress and yield strain of the compression molded,cured, elastomer/cellulose ester composition samples were measured asper ASTM D412 and are shown in Table 12.

TABLE 12 Composition Modulus, Yield Stress, Yield Strain, Number MPa MPa% 3.1 6.99 1.37 22.11 3.2 7.47 1.26 19.25 3.3 7.32 1.29 20.45 3.4 12.121.83 17.29 3.5 13.45 1.84 14.8 3.6 11.47 1.89 17.99 3.7 13.36 2.07 17.933.8 8.43 1.37 18.57 3.9 11.36 1.54 14.83 3.10 10.67 1.44 15.92

These data show that for Composition Numbers 3.2-3.11, the modulus wasimproved over Comparative Composition 3.1.

Example 4 Use of Cellulose Esters and Plasticizers in Tire Formulations

This example is provided to show the advantages of the use of celluloseesters with plasticizers in tire formulations over cellulose estersalone. Table 13 shows the tire formulations. All amounts in Table 13 arebased on parts per hundred rubber (phr). Table 14 shows the celluloseester/plasticizer masterbatch formulations.

Table 15 shows the mixing conditions. The components were mixed in aBanbury mixer, which was a Farrel BR mixer with steam heating and watercooling which is instrumented with computer monitors for temperature,rpm, and power. After preparing the elastomer/celluloseester/plasticizer composition, the composition was cured T₉₀+5 minutesat 320° F. (160° C.).

TABLE 13 Formulations of Cellulose Ester-Filled Tire Tread CompoundsIngredients Sample Name CAB-1 CAB-2 CAB-3 Stage 1 Buna VSL 5025-2¹S-SBR, 37.5phr 103.12 103.12 103.12 TDAE² Buna CB24³ PBD rubber 25 25 25Rhodia 1165 MP Silica 70 70 70 Si69⁴ Coupling agent 5.47 5.47 5.47Sundex ® 790⁵ Aromatic Oil 5 5 5 Stearic acid Cure Activator 1.5 1.5 1.5Stage 2 Product of stage 1 210.09 210.09 210.09 Cellulose Ester MB⁶ MB -1 10 MB - 2 12.5 MB - 3 12.5 Zinc oxide Cure activator 1.9 1.9 1.9Okerin ® wax 7240⁷ microcrystalline 1.5 1.5 1.5 wax Santoflex ® 6PPD⁸Anti-oxidant 2 2 2 KK49⁹ process aid 2 2 2 Stage 3 Product of stage 2217.49 229.99 229.99 Sulfur Cross-linker 1.5 1.5 1.5 Santocure ® CBS¹⁰Accelerator 1.3 1.3 1.3 Perkacit ® DPG- Accelerator 1.5 1.5 1.5 grs¹¹Total 221.79 234.29 234.29 ¹S-SBR—solution styrene butadiene rubberobtained from Lanxess. ²TDAE—treated distillate aromatic extract³PBD—polybutadiene rubber obtained from Lanxess ⁴Si69 is asulfur-containing organosilane obtained from Arkema ⁵Sundex ® 790 is anaromatic oil obtained from Sunoco ⁶MB—Masterbatch ⁷Okerin ® wax 7240 isa microcrystalline wax obtained from Sovereign Chemical ⁸Santoflex 6PPDis an anti-oxidant obtained from Flexsys. ⁹KK49 is a processing aidobtained from Strutkol. ¹⁰Santocure ® CBS is an accelerator obtainedfrom Flexsys. ¹¹Perkacit ® DPG-grs is an accelerator obtained fromFlexsys.

TABLE 14 Compositions of Plasticized Cellulose Ester Masterbatches Tgbefore Plasticizer Pz level PHR of MB in Tg after MB-Y CE Plasticizer,C. (Pz) (g/100 g CE) formulation plasticizer, C. MB-1 CAB 381-2 133 None— 10 133 MB-2 CAB 381-2 133 EMN 168¹ 25 12.5 95 MB-3 CAB 381-2 133PEG-300² 25 12.5 70

TABLE 15 Processing of Cellulose-Ester Filled Tire Tread Compounds in aBanbury Mixer Stage 1 mix conditions Start temperature 65° C. Startingrotor speed, rpm 65 Fill factor 67% Mix sequence at 0 minute addelastomers at 1 minute add ⅔ silica + Si69 at 2 minute add ⅓ silica +others at 3 minute sweep at 3.5 minute increase rotor speed to ramptemperature to 160° C. in 4.5 minutes Dump Condition hold 2 minutes at160° C. (Total mix time = 6.5 minutes) Stage 2 mix conditions Starttemperature 65° C. Starting rotor speed, rpm 65 Fill factor 64% Mixsequence at 0 minute add ½ of first pass batch at 15 second add otheringredients in a pocket and ½ of first pass batch at 1 minute sweep at1.5 minute increase rotor speed to ramp temperature to 140-145° C. in3.5 minutes Dump Condition Hold 4 minutes at 140-145° C. (total mix time= 7.5 minutes) Stage 3 mix conditions Start temperature 50° C. Startingrotor speed, rpm 60 Fill factor 61% Addition order at 0 minute add ½ 2ndpass batch, at 15 second add sulfur, accelerators and ½ 2nd pass batch,sweep at 1 minute. Dump conditions 110° C. or 2 minute 30 second

TABLE 16 Performance of Cellulose Ester-Filled Tire Tread CompoundsCAB-2 CAB-3 CAB-1 CAB 381-2 + CAB 381-2 + Properties CAB 381-2 25 phcE168 25 phc PEG Compounding Mooney viscosity, 4 63.5 58.5 55.1 minute at100° C. Cured Rubber Phillips Dispersion 1 4 4 Break stress, psi 21912240 2349 Break strain, % 386 387 366 Modulus(M100), psi 663 679 735Modulus (M300), psi 1693 1723 1918 Shore A Hardness 61 59 62 Tan Delta0° C. 0.306 0.292 0.313 Tan Delta 60° C. 0.082 0.081 0.076 Rebound 0°C., % 9.8 10.8 9.6 Rebound 60° C., % 62.2 62.8 64.0 Wear, volume loss in136 124 127 mm³

Performance Measurement:

Descriptions of various analytical techniques used to measureperformance are provided below:

-   -   Mooney Viscosity: The Mooney Viscosities were measured according        to ASTM D 1646.    -   PHILLIPS Dispersion Rating: The samples were cut with a razor        blade, and pictures were taken at 30× magnification with an        Olympus SZ60 Zoom Stereo Microscope interfaced with a PaxCam ARC        digital camera and a Hewlett Packard 4600 LaserJet color        printer. The pictures of the samples were then compared to a        Phillips standard dispersion-rating chart having standards        ranging from 1 (bad) to 10 (excellent).    -   Mechanical Properties Break stress, break strain, modulus at        100%, and 300% strains were measured as per ASTM D412 using Die        C for specimen preparation. The speed of testing was 20        inches/min, and the gauge length was 63.5 mm (2.5 inch). The        samples were conditioned in the lab for 40 hours at 50%+/−5%        humidity and 72° F. The width of specimen was 1 inch, and length        was 4.5 inch.    -   Hardness: Shore A hardness was measured according to ASTM D2240.    -   Dynamic Mechanical Analysis—Temperature Sweep: A TA instruments        Dynamic Mechanical Analyzer was used to complete the temperature        sweeps using a tensile geometry. Storage modulus (E′), Loss        modulus (E″), and tan delta (=E″/E′) were measured as a function        of temperature from −80° C. to 120° C. using 10 Hz frequency,        and 5% static and 0.2% dynamic strain.    -   Rebound Test The rebound pendulum test was carried out as per        ASTM D7121-05.    -   Wear: Din abrasion testing was performed per ASTM 222.

The data show that without the use of a plasticizer, the cellulose esterdid not disperse as well through the elastomer as shown by the poorPhillips Dispersion data. Further, the Mooney viscosities of thecompositions containing both cellulose ester and plasticizer were lowerthan when plasticizer was not utilized. This shows that in the presenceof the plasticizer, CEs acted as a processing aid and lowered Mooneyviscosity. Furthermore, the break stress and wear was also improved overcompositions without plasticizer, presumably indicating that in presenceof the plasticizers, CEs can disperse into finer particles and canimprove the properties that are dependent on particle size and/orsurface area.

Example 5 Use of Modified Cellulose Esters in Tire Tread Formulations

This example is provided to show the advantages of the use of celluloseesters with plasticizers in tire formulations over formulations withoutcellulose esters. Table 17 shows the cellulose ester and plasticizermasterbatch formulations that are utilized in the tire formulations.Table 18 shows the tire formulations, and Table 19 shows the mixingconditions.

TABLE 17 Cellulose Ester/Plasticizer Masterbatches Quantity in CE SampleComposition formulation (phr) CAB553DOA¹ CAB 553-0.4 w/ 20 phCE 15 DOACAB381DOA CAB 381-0.1 w/ 10 phCE 18 DOA CAP482DOA CAP 482-0.5 w/ 25 phCE16.5 DOA CAB381TEG² CAB-381-0.1 w/ 10 phCE 18.75 TEG-EH CAB381PEG³CAB-381-0.1 w/ 10 phCE 16.5 PEG CAB381ESO⁴ CAB-381-0.1 w/ 15 phCE 16.5ESO CAP482Triacetin⁵ CAP 482-0.5 w/ 30 phCE 19.5 Triacetin CAP482PEG CAP482-0.5 w/ 20 phCE 18 PEG CAB381Triton⁶ CAB 381-0.1 w/ 10 phCE 16.5Triton X100 ¹DOA—dioctyl adipate ²TEG-EH—triethylene glycol bis(2-theylhexanoate) ³PEG—poly(ethylene glycol), Mol. Wt. - 300 ⁴ESO—epoxidizedsoybean oil ⁵Triacetin—glyceryl triacetate ⁶Triton ® X100—ethyoxylatedoctylphenol obtained from Dow Chemical

TABLE 18 Tire Formulations Ingredients Sample name Si65 Si80 Si65Oil15CE Samples Stage 1 Buna VSL 5025-2 S-SBR¹, 37.5 phr TDAE² 89.38 89.3889.38 89.38 Buna CB 24 PBD³ rubber 35 35 35 35 Ultrasil ® 7000 GR⁴Silica 65 80 65 65 N234 Carbon black 15 15 15 15 Si 266 Coupling agent5.08 6.24 5.08 5.08 Sundex ® 790⁵ Aromatic oil 15 Stearic acid CureActivator 1.5 1.5 1.5 1.5 Product of Stage 1 MB1 210.96 227.12 225.96210.96 Stage 2 Product of Stage 1 MB1 210.96 227.12 225.96 210.96 CEproduct (Table 1) Cellulose Ester As in Table 1 Si 69 Coupling agent1.17 Zinc oxide Cure activator 1.9 1.9 1.9 1.9 Okerin ® wax 7240⁶microcrystalline wax 1.5 1.5 1.5 1.5 Santoflex ® 6PPD⁷ Anti-oxidant 2 22 2 Product of Stage 2 MB2 216.36 232.52 231.36 217.53 + CE Stage 3Product of Stage 2 MB2 216.36 232.52 231.36 217.53 + CE SulfurCross-linker 1.28 1.28 1.28 1.28 Santocure ® CBS⁸ Accelerator 1.1 1.11.1 1.1 Perkacit ® DPG-grs⁹ Accelerator 1.28 1.28 1.28 1.28 Total 220.02236.18 235.02 221.19 + CE ¹S-SBR—solution styrene butadiene rubberobtained from Lanxess. ²TDAE—treated distillate aromatic extract³PBD—polybutadiene rubber obtained from Lanxess ⁴Ultrasil 7000 GR silicaobtained from Evonik Industries ⁵Sundex ® 790 is an aromatic oilobtained from Sunoco ⁶Okerin ® wax 7240 is a microcrystalline waxobtained from Sovereign Chemical ⁷Santoflex ® 6PPD is an anti-oxidantobtained from Flexsys. ⁸Santocure ® CBS is an accelerator obtained fromFlexsys. ⁹Perkacit ® DPG-grs is an accelerator obtained from Flexsys.

Banbury Mixing: The mixer is a Farrel BR mixer with steam heating andwater cooling which is instrumented with computer monitors fortemperature, rpm, and power.

Curing: The compounds were cured 30 minutes at 320° F. (160° C.).

TABLE 19 Processing of Cellulose Ester-filled Tire Tread Compounds in aBanbury mixer Stage 1 mix conditions Start temperature 65° C. Startingrotor speed, rpm 65 Fill factor 67% Ram pressure 50 Mix sequence at 0min add elastomers at 1 min add ⅔ silica + Si266 at 2 min add ⅓ silica +others at 3 min sweep at 3.5 min adjust (increase) rotor speed toincrease temperature to 160° C. Dump conditions hold 2 min at 160° C.(total mix time = 6.5 min) Stage 2 mix conditions start temperature 65°C. starting rotor speed, rpm 65 fill factor 64% ram pressure 50 mixsequence at 0 min add ½ of first pass batch At 15 s add otheringredients and 1/2 of first pass batch at 1 min sweep. at 1.5 minadjust (increase) rotor speed, ramp temperature to 150° C. dumpconditions hold 4 min at 150° C. (Total mix time = 7.5 min) Stage 3 mixconditions start temperature 50° C. starting rotor speed, rpm 60 fillfactor 61% ram pressure 50 addition order at 0 min ½ 2nd pass batch, at15 s add sulfur, accelerator package, & ½ 2nd pass batch, sweep at 1min. dump conditions 110° C. or 2 min 30 s

Performance of the tire formulations are shown in Table 20.

Test Descriptions for Example 5:

Cure Rheometer: Oscillating Disk Rheometer (ODR) was performed accordingto ASTM D 2084. ts2 is the time it takes for the torque of the rheometerto increase 2 units above the minimum value. tc90 is the time to reach90% of the difference between minimum to maximum torque.

The Mooney Viscosities were measured according to ASTM D 1646.

Phillips Dispersion Rating: The samples were cut with a razor blade, andpictures were taken at 30× magnification with an Olympus SZ60 ZoomStereo Microscope interfaced with a PaxCam ARC digital camera and aHewlett Packard 4600 LaserJet color printer. The pictures of the sampleswere then compared to a Phillips standard dispersion-rating chart havingstandards ranging from 1 (bad) to 10 (excellent)

Dynamic Mechanical Analysis (Strain Sweeps): Metravib DMA150 DynamicMechanical Analyzer was used in shear deformation to perform a doublestrain sweep experiment (simple shear 10 mm×2 mm). The experimentalconditions were 0.001 to 0.5 dynamic strain at 13 points in evenlyspaced log steps at 30° C. and 10 Hz.

Hot Molded Groove Trouser Tear (at 100° C.): Molded groove trouser tear(Type CP modified trouser tear test piece with a constrained path fortear) was performed according to ASTM test method D624.

Break stress and break strain were measured as per ASTM D412 using Die Cfor specimen preparation. The speed of testing was 20 inches/min, andthe gauge length was 63.5 mm (2.5 inch). The samples were conditioned inthe lab for 40 hours at 50%+/−5% humidity and 72° F. The width ofspecimen was 1 inch and length was 4.5 inch.

Dynamic Mechanical Analysis (Temperature Sweeps): TA instrument DynamicMechanical Analyzer was used in tensile mode to perform the temperaturesweep experiment. The experimental conditions were 0.5 static and 0.5dynamic strain from −20° C. to 120° C. at 10 Hz.

TABLE 20 Performance of Cellulose Ester-filled Tire Tread CompoundsMooney DMA (5% DMA (5% Molded DMA (5% After 4 min stain in stain inGroove strain in at 100° C. Phillips shear) Stor- shear) Tear at Breaktension) Tc90 Ts2 (Mooney Dispersion age Modulus Tan Delta 100° C.stress Break Tan Delta Sample Name (min) (min) Units) Rating at 30° C.(Pa) at 30° C. lbf/in psi strain % at 0° C. Si65 10.9 2.26 82.3 71800000 0.265 119 2720.4 381.5 0.4019 Si80 13.1 2 94.3 7 2330000 0.329114 2475.1 298.5 0.4445 Si65Oil15 11 2.57 60.7 4 1410000 0.256 1322471.8 428.1 0.4273 CAB553DOA 9.68 2.34 72 6 2010000 0.279 168 2709.5457.8 0.4121 CAB381DOA 10.3 2.56 69.8 4 1960000 0.263 140 2911.4 424.40.4027 CAP482DOA 10.3 2.53 75.3 7 1930000 0.26 212 2599.4 431.8 0.3854CAB381TEG 10.3 2.48 72.1 5 1990000 0.267 144 2776.5 414.4 0.4177CAB381PEG 11.3 2.71 71 6 1980000 0.27 156 2857.8 402.4 0.4097 CAB381ESO11.5 2.75 71.9 7 2090000 0.285 157 2640.6 402.9 0.43 CAP482Triacetin11.3 2.99 72 7 2000000 0.286 174 2660.8 415.4 0.4492 CAP482PEG 9.3 2.4476.3 7 2280000 0.274 215 2991.4 522 0.4445 CAB381Triton 11.6 2.9 74 72250000 0.288 135 2704 386.5 0.4365

Data Discussion:

Table 20 shows the samples and corresponding performance measurements.There were three controls and nine modified cellulose esters included inTable 20. Si65, Si80 and Si65Oil15 were controls with 65 phr silica, 80phr silica and 65 phr silica/15 phr additional oil, respectively, asdetailed in Table 18. All of the modified cellulose ester formulationscontain 65 phr silica and 15 phr modified cellulose ester.

Compared to control (Si65), addition of 15 phr CE provides the followingimprovements. The Tc90 data produced from the cure rheometer showedcomparable or slightly faster cure times. Shorter cure times aredesirable as this provides for faster turnaround times in curing moldsand presses. The Ts2 data from the cure rheometer which indicates thescorch/handling time before onset of cure showed significantly longerhandling/flowing/molding time over the Si65 control. The Mooneyviscosity data of the inventive examples were significantly lower thanthe Si65 control showing that the addition of the cellulose ester andplasticizer provided for better processability of the celluloseester/elastomer composition. The dispersion rating which indicates thequality of the filler dispersion was comparable to the Si65 control. Thedynamic mechanical analysis strain modulus was improved over the Si65control. The molded groove tear at 100° C. was significantly better thanthe Si65 control, and the dynamic mechanical analysis Tan Delta at 0° C.(wet traction) also showed significant improvement. The break stress andbreak strain data (compound cure/processing indicator) were all withintarget ranges.

In contrast, addition of 15 phr Si (Si80) had a detrimental effect onseveral properties, including Tc90, Ts2, Mooney viscosity, rollingresistance and break strain. Addition of 15 phr oil (Si65Oil15) had verysignificant detrimental effect on low strain modulus.

Example 6 Use of Modified Cellulose Esters in Various Tire TreadFormulations

A) Various Tire Tread Formulation were prepared as shown in Table. 21.

B) Processing

Banbury Mixing: The mixer was a Farrel BR mixer with steam heating andwater cooling which was instrumented with computer monitors fortemperature, rpm, and power. The processing of the celluloseester-filled tire tread compounds in a Banbury mixer were the same asshown in Table 19 in Example 5.

Curing: The compounds were cured 30 minutes at 320° F. (160° C.).

C) Performance

Test Descriptions are the same as in Example 5.

Performance of the tire formulations are shown in Table 22

D) Data Discussion:

Control 1 vs. CE 1: CE on top of formulation. Improved viscosity (lowerbetter, processability), low strain modulus (higher better, handling),tear (higher better), and tan delta at 0° C. (higher better, wettraction) and no significant negative impact on other propertiesmeasured.

Control 2 vs. CE 2: Cellulose ester replaced silica. Improved viscosity(lower better, processability), tan delta at 30° C. (lower better,rolling resistance) tear (higher better), but slightly worst low strainmodulus (higher better, handling) and no significant negative impact onother properties measured.Control 3 vs. CE 3: Cellulose ester replaced oil. Improved low strainmodulus (higher better, handling), tear (higher better), but slightlyworst viscosity (lower better, processability), and no significantnegative impact on other properties measured.

TABLE 21 Tire Formulations Ingredients Sample name Control 1 CE 1Control 2 CE 2 Control 3 CE 3 Stage 1 Buna VSL 4041 S-SBR¹ 65 65 65 6565 65 Buna CB 24 PBD² rubber 35 35 35 35 35 35 Ultrasil ® 7000 GR³Silica 63 63 70 62 54 53 N234 Carbon black 5 5 5 5 5 5 Si 266 Couplingagent 4.91 4.91 5.46 4.84 4.21 4.13 Tudalin 4192⁴ Aromatic oil 33 33 2625 28 22 Stearic acid Cure Activator 1.5 1.5 1.5 1.5 1.5 1.5 Product ofStage 1 MB1 207.41 207.41 207.96 198.34 192.71 185.63 Stage 2 Product ofStage 1 MB1 207.41 207.41 207.96 198.34 192.71 185.63 CAB381-0.5 w/22phCE Triton ® X100 Cellulose Ester 0 8 0 9 0 7 Si 266 Coupling agent 00.624 0 0.702 0 0.546 Zinc oxide Cure activator 1.9 1.9 1.9 1.9 1.9 1.9Okerin ® wax 7240⁵ microcrystalline wax 1.5 1.5 1.5 1.5 1.5 1.5Santoflex ® 6PPD⁶ Anti-oxidant 2 2 2 2 2 2 Product of Stage 2 MB2 212.81221.44 213.36 213.44 198.11 198.58 Stage 3 Product of Stage 2 MB2 212.81221.44 213.36 213.44 198.11 198.58 Sulfur Cross-linker 1.28 1.28 1.281.28 1.28 1.28 Santocure ® CBS⁷ Accelerator 1.1 1.1 1.1 1.1 1.1 1.1Perkacit ® DPG-grs⁸ Accelerator 1.28 1.28 1.28 1.28 1.28 1.28 Total216.47 225.1 217.02 217.1 201.77 202.24 ¹S-SBR—solution styrenebutadiene rubber obtained from Lanxess. ²PBD—polybutadiene rubberobtained from Lanxess ³Ultrasil 7000 GR silica obtained from EvonikIndustries ⁴Tudelen 4192—treated distillate aromatic extract obtained bythe H&R Group ⁵Okerin ® wax 7240 is a microcrystalline wax obtained fromSovereign Chemical ⁶Santoflex ® 6PPD is an anti-oxidant obtained fromFlexsys. ⁷Santocure ® CBS is an accelerator obtained from Flexsys.⁸Perkacit DPG-grs is an accelerator obtained from Flexsys.

TABLE 22 Performance of Cellulose Ester-filled Tire Tread CompoundsMooney DMA (5% Molded DMA (5% After 4 min stain in shear) DMA (5% Groovestrain in at 100° C. Storage stain in shear) Tear at Break Breaktension) Tan Sample Tc90 Ts2 (Mooney Modulus at Tan Delta at 100° C.stress strain Delta at Name (min) (min) Units) 30° C. (Pa) 30° C. lbf/inpsi % 0° C. Control 1 13.4 3.99 40.2 1.14E+06 0.214 86.9 2342 686 0.323CE 1 11.6 4.37 36.4 1.20E+06 0.202 92.8 2352 644 0.368 Control 2 13.43.05 54.2 1.59E+06 0.247 77.9 2376 565 0.386 CE 2 10.5 3.52 45.01.47E+06 0.207 94.9 2563 626 0.378 Control 3 10.4 3.43 39.6 1.11E+060.183 70.3 2463 628 0.344 CE 3 8.4 3.33 42.5 1.33E+06 0.188 73.7 2669653 0.333

That which is claimed is:
 1. A tire comprising a celluloseester/elastomer composition wherein said cellulose ester/elastomercomprising at least one cellulose ester, at least one elastomer, and atleast one additive selected from the group consisting of at least onecompatibilizer and at least one plasticizer.
 2. The tire according toclaim 1 wherein said cellulose ester has an inherent viscosity (IV) ofabout 0.2 to about 3.0 deciliters/gram.
 3. The tire according to claim 1wherein said cellulose ester has a total degree of substitution peranhydroglucose unit (DS/AGU) from about 0.5 to about 2.8.
 4. The tireaccording to claim 1 wherein the cellulose ester is a low molecularweight cellulose mixed ester selected from the group consisting of: a) alow molecular weight mixed cellulose ester having the followingproperties: a total degree of substitution per anhydroglucose unit offrom about 3.08 to about 3.50, having the following substitutions: adegree of substitution per anhydroglucose unit of hydroxyl of no morethan about 0.70, a degree of substitution per anhydroglucose unit ofC₃-C₄ esters from about 0.80 to about 1.40, and a degree of substitutionper anhydroglucose unit of acetyl of from about 1.20 to about 2.34; aninherent viscosity of from about 0.05 to about 0.15 dL/g, as measured ina 60/40 (wt./wt.) solution of phenol/tetrachloroethane at 25° C.; anumber average molecular weight (M_(n)) of from about 1,000 to about5,600; a weight average molecular weight (M_(w)) of from about 1,500 toabout 10,000; and a polydispersity of from about 1.2 to about 3.5; andb) a low molecular weight mixed cellulose ester having the followingproperties: a total degree of substitution per anhydroglucose unit offrom about 3.08 to about 3.50, having the following substitutions: adegree of substitution per anhydroglucose unit of hydroxyl of no morethan about 0.70; a degree of substitution per anhydroglucose unit ofC₃-C₄ esters from about 1.40 to about 2.45, and a degree of substitutionper anhydroglucose unit of acetyl of from about 0.20 to about 0.80; aninherent viscosity of from about 0.05 to about 0.15 dL/g, as measured ina 60/40 (wt./wt.) solution of phenol/tetrachloroethane at 25° C.; anumber average molecular weight (M_(n)) of from about 1,000 to about5,600; a weight average molecular weight (M_(w)) of from about 1,500 toabout 10,000; and a polydispersity of from about 1.2 to about 3.5; andc) a low molecular weight mixed cellulose ester having the followingproperties: a total degree of substitution per anhydroglucose unit offrom about 3.08 to about 3.50, having the following substitutions: adegree of substitution per anhydroglucose unit of hydroxyl of no morethan about 0.70; a degree of substitution per anhydroglucose unit ofC₃-C₄ esters from about 2.11 to about 2.91, and a degree of substitutionper anhydroglucose unit of acetyl of from about 0.10 to about 0.50; aninherent viscosity of from about 0.05 to about 0.15 dL/g, as measured ina 60/40 (wt./wt.) solution of phenol/tetrachloroethane at 25° C.; anumber average molecular weight (M_(n)) of from about 1,000 to about5,600; a weight average molecular weight (M_(w)) of from about 1,500 toabout 10,000; and a polydispersity of from about 1.2 to about 3.5. 5.The tire according to claim 1 wherein said cellulose ester is afunctionalized cellulose ester wherein said functionalized celluloseester is functionalized by at least one bifunctional reactant producinga cellulose ester with at least one functional group selected from thegroup consisting of unsaturation (double bonds), carboxylic acids,acetoacetate, acetoacetate imide, mercapto, melamine, and long alkylchains.
 6. The tire according to claim 1 wherein said plasticizer is atleast one selected from the group consisting of a phosphate plasticizer,benzoate plasticizer, adipate plasticizer, a phthalate plasticizer, aglycolic acid ester, a citric acid ester plasticizer and ahydroxyl-functional plasticizer.
 7. The tire according to claim 6wherein said plasticizer is at least one selected from the groupconsisting of triphenyl phosphate, tricresyl phosphate, cresyldiphenylphosphate, octyldiphenyl phosphate, diphenylbiphenyl phosphate, trioctylphosphate, tributyl phosphate, diethyl phthalate, dimethoxyethylphthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate,di-2-ethylhexyl phthalate, butylbenzyl phthalate, dibenzyl phthalate,butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methylphthalyl ethyl glycolate, triethyl citrate, tri-n-butyl citrate,acetyltriethyl citrate, acetyl-tri-n-butyl citrate, andacetyl-tri-n-(2-ethylhexyl)citrate.
 8. The tire according to claim 1wherein said plasticizer is selected from at least one of the following:esters comprising: (i) acid residues comprising one or more residues of:phthalic acid, adipic acid, trimellitic acid, succinic acid, benzoicacid, azelaic acid, terephthalic acid, isophthalic acid, butyric acid,glutaric acid, citric acid or phosphoric acid; and (ii) alcohol residuescomprising one or more residues of an aliphatic, cycloaliphatic, oraromatic alcohol containing up to about 20 carbon atoms.
 9. The tireaccording to claim 1 wherein said plasticizer comprises alcohol residueswhere the alcohol residues is at least one selected from the following:stearyl alcohol, lauryl alcohol, phenol, benzyl alcohol, hydroquinone,catechol, resorcinol, ethylene glycol, neopentyl glycol,1,4-cyclohexanedimethanol, and diethylene glycol.
 10. The tire accordingto claim 1 wherein said plasticizer is selected from the groupconsisting of aliphatic polyesters comprising C₂₋₁₀ diacid residues andC₂₋₁₀ diol residues; wherein said C₂₋₁₀ diacid residue is at least oneselected from the group consisting of malonic acid, succinic acid,glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid,and sebacic acid.
 11. The tire according to claim 1 wherein saidplasticizer comprises diol residues; wherein said diol residues is atleast one of the following C₂-C₁₀ diols: ethylene glycol, diethyleneglycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol,1,3-butylene glycol, 1,4-butylene glycol, neopentyl glycol,1,5-pentanediol, 1,6 hexanediol, 1,5-pentylene glycol, triethyleneglycol, and tetraethylene glycol.
 12. The tire according to claim 1wherein said plasticizer comprises one or more of: A) from about 5 toabout 95 weight % of a C₂-C₁₂ carbohydrate organic ester, wherein thecarbohydrate comprises from about 1 to about 3 monosaccharide units; andB) from about 5 to about 95 weight % of a C₂-C₁₂ polyol ester, whereinthe polyol is derived from a C₅ or C₆ carbohydrate.
 13. The tireaccording to claim 1 wherein said plasticizer comprises at least onecarbohydrate ester and said carbohydrate portion of the carbohydrateester comprises an α-anomer, a β-anomer or a mixture thereof.
 14. Thetire according to claim 1 wherein said compatibilizer is a non-reactivecompatibilizer; wherein said non-reactive compatibilizer contains afirst segment that is compatible with said cellulose ester and a secondsegment that is compatible with said elastomer.
 15. The tire accordingto claim 14 wherein said first segment of said non-reactivecompatibilizer is at least one oligomer or polymer selected from thegroup consisting of cellulose esters; cellulose ethers,polyoxyalkylenes, polyglycols, polyesters, polyacrylates,polymethacrylates, polyacetals, polyvinylpyrrolidone, polyvinyl acetate,and polyvinyl alcohol.
 16. The tire according to claim 14 wherein saidsecond segment of said non-reactive compatibilizer is selected from thegroup consisting of polyolefins, polydienes, polyaromatics, andcopolymers.
 17. The tire according to claim 14 wherein said non-reactivecompatibilizers are selected from the group consisting of ethoxylatedalcohols, ethoxylated alkylphenols, ethoxylated fatty acids, blockpolymers of propylene oxide and ethylene oxide, polyglycerol esters,polysaccharide esters, and sorbitan esters.
 18. The tire according toclaim 1 wherein said compatibilizer is a reactive compatibilizer whereinsaid reactive compatibilizer has a hydrocarbon chain that is compatiblewith said elastomer and has at least one functional group capable ofreacting with said cellulose ester.
 19. The cellulose ester/elastomercomposition according to claim 18 wherein said reactive compatibilizeris selected from the group consisting of long chain fatty acids, longchain fatty acid chlorides, long chain fatty acid anhydrides, epoxidizedoils and fatty esters, styrene maleic anhydride copolymers, maleicanhydride grafted polypropylene, copolymers of maleic anhydride witholefins and/or acrylic esters, and copolymers of glycidyl methacrylatewith olefins and/or acrylic esters.
 20. The cellulose ester/elastomercomposition according to claim 18 wherein said reactive compatibilizerhas a polar chain that is compatible with said cellulose ester and alsohas at least one functional group capable of reacting with saidelastomer.